Novel polyol composition and the use thereof in the preparation of rigid polyurethane foams

ABSTRACT

The present invention is directed to a novel polyol composition and the use thereof in the preparation of a rigid polyurethane foam. More particularly the polyol composition is a blend of specific amounts of two polyols, one based on ortho-toluene diamine and the other based on a non-ortho-toluene diamine.

BACKGROUND OF THE INVENTION

Reaction products of ortho-toluene diamine and alkylene oxides have beendescribed in the art (note British Patent No. 1,311,095). Also describedin the art is the propoxylated product of a mixture of 51% by weight ofortho-toluene diamine and 49% by weight of meta-toluene diamine (seeExample 3 of the above identified British patent).

Toluene diamine initiated polyols derived from ethylene and propyleneoxide are also known and described in the art (see U.S. Pat. Nos.4,209,609 and 4,243,759). Alkylene oxide adducts of ortho-toluenediamine are also known. U.S. Pat. No. 4,562,290 describes adductsprepared by first reacting one to three moles of ethylene oxide withortho-toluene diamine, and then reacting the resultant product with fromfour to eight moles of propylene oxide. The resultant products aredescribed as being useful in the production of rigid polyurethane foams.The `290 patent suggests that the adducts described therein can beblended with a variety of different polyols. Among the polyols suggestedas being useful are alkylene oxide adducts of a variety of differentaromatic amines including 2,4-diaminotoluene.

Finally, a variety of different adducts of ortho-toluene diamines andalkylene oxides are described in U.S. Pat. Nos. 4,397,966, 4,410,641,4,421,871, 4,469,822, and 4,767,795.

While all these various adducts based on ortho-toluene diamine have beenknown for some time, they have not met with any substantial commercialsuccess primarily because when substituted for more conventionalpolyols, the resultant foams will vary in k-factor, and various physicalproperties with variations in product density.

DESCRIPTION OF THE INVENTION

The present invention is directed to a novel polyol composition and itsuse in the production of rigid polyurethane foams to be used in theappliance industry. The novel polyol composition of the presentinvention provides foams at varying densities having comparable thermalproperties (i.e. k-factor) while maintaining physical properties andhaving good processing and excellent demold properties. Molded coredensities in foams used in the appliance industry typically range from1.45 pounds per cubic foot to 2.00 pounds per cubic foot. Moreparticularly, the present invention is directed to a polyol compositioncomprising:

(a) an adduct obtained by sequentially reacting 2,4- and/or 2,6-toluenediamine with from 3 to 5 moles of ethylene oxide and then with from 1 to5.1 moles of propylene oxide, the total number of moles of ethyleneoxide plus propylene oxide being at least 5 and no more than 8.1, and

(b) an adduct obtained by sequentially reacting 2,3- and/or 3,4-toluenediamine with from 1 to 5 moles of ethylene oxide and then with from 1 to6 moles of propylene oxide, the total number of moles of ethylene oxideplus propylene oxide being at least 5 and no more than 9, the weightratio of component (a) to component (b) being from 35:65 to 70:30, andpreferably from 50:50 to 70:30, and most preferably 50:50.

The adducts used herein are known in the art. Thus, adducts based on2,4- and/or 2,6-toluene diamine and their method of manufacture aredescribed in U.S. Pat. Nos. 4,209,609 and 4,243,759, the disclosures ofwhich are herein incorporated by reference. The adducts based on 2,3-and/or 3,4-toluene diamine and their methods of manufacture aredescribed in U.S. Pat. Nos. 4,562,290, and 4,767,795, the disclosures ofwhich are herein incorporated by reference.

The novel polyol compositions herein are used to prepare polyurethanefoams.

The various methods for the preparation of polyurethane foams are wellknown in the art and do not require detailed discussion; see, forexample, Dombrow, "Polyurethanes," Reinhold Publishing Corporation, NewYork, pages 1-105 (1957); Saunders et al, "Polyurethanes", Part I,Interscience Publishers, New York (1962). One common procedure consistsin reacting a polyol, for example, a polyester or polyether, with anorganic polyisocyanate and with a blowing agent, if necessary in thepresence of catalysts, surface active agents or other auxiliary agents,whereby simultaneous interaction between the isocyanate, blowing agentand the polyol occurs to give the required foam product. This is theso-called "one-shot" procedure. Alternatively, the polyol may be reactedwith sufficient polyisocyanate to give an intermediate reaction productcontaining free isocyanate groups and this product, known as prepolymer,may then be reacted with water, if desired in the presence of catalyst,surface active agents or other auxiliary agents, in order to produce thefinal foamed product. This latter is the so-called "prepolymer" process.Many variations in the method of carrying out these basic processes areknown.

Any of the prior art polyisocyanates conventionally used in thepreparation of rigid polyurethane foams can be employed in the processof the present invention. Illustrative of such isocyanates are2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate,4,4'-diphenylmethane diisocyanate, dianisidine diisocyanate, tolidinediisocyanate, hexamethylene diisocyanate, m-xylylene diisocyanate,1,5-naphthalene diisocyanate, and other di- and higher polyisocyanatessuch as those listed in the tables of Siefken, Ann. 562, 122-135 (1949).Mixtures of two or more of the above isocyanates can be used if desired.Preferred polyisocyanates are products obtained by phosgenation ofmixtures of methylene-bridged polyphenyl polyamines obtained by theinteraction of formaldehyde, hydrochloric acid, and primary aromaticamine, for example, aniline, o-chloroaniline, o-toluidine, or mixturesthereof. Such polyisocyanates are known in the art, e.g., U.S. Pat. Nos.2,683,730, 2,950,263 and 3,012,008; Canadian Patent No. 665,495; andGerman Patent No. 1,131,877. A particularly preferred polyisocyanate ofthis type is the polymethylene poly(phenylisocyanate) availablecommercially as Mondur MR, from Mobay Corporation.

In preparing polyurethane foams according to the invention, it isdesirable, in accordance with conventional procedures, to employ acatalyst in the reaction of the polyisocyanate and polyol. Any of thecatalysts conventionally employed in the art to catalyze the reaction ofan isocyanate with reactive hydrogen containing compounds can beemployed for this purpose; see, for example, Saunders et al., Ibid,Volume I, pages 228-232; see, also Britain et al., "J. Applied PolymerScience," 4,207-4,211, 1960. Such catalysts include organic andinorganic acid salts of and organometalic derivatives of, bismuth, lead,tin, iron, antimony, uranium, cadmium, cobalt, thorium, aluminum,mercury, zinc, nickel, cerium, molybdenum, vanadium, copper, manganese,and zirconium, as well as phosphines and tertiary organic amines. Thepreferred catalysts for use in the process and compositions of theinvention are the tertiary organic amines of which the following arerepresentative: triethylamine, triethylenediamine,N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetraethylethylenediamine, N-methylmorpholine, N-ethylmorpholine,N,N,N',N'-tetramethylguanidine, N,N,N',N'-tetramethyl-1,3-butanediamine,N,N-dimethylethanolamine, N,N-diethylethanolamine, and the like, ormixtures of two or more such amines. The amount of catalyst employed isgenerally within the range of about 0.1 to about 2.0% by weight based ontotal weight of reactants in the polyurethane forming reaction mixture.

The ratio of isocyanate groups to active hydrogen containing groups inthe foam mixtures of the invention is within the normal limits employedin the production of polyurethane foams. This ratio is advantageouslywithin the range of from 1.50 to 0.65:1 and preferably within the rangeof 1.20:1 to 1:1, whether the isocyanate and polyol are employedseparately in the one-shot process or whether the two components havebeen reacted to form a prepolymer.

The final foam density of the products produced by the process of theinvention can be controlled in accordance with methods well known in theart. For example, this control can be accomplished by regulating theamount of water present in the foam mixture or by using a combination ofwater and a conventional blowing agent having a boiling point belowabout 110° C. and preferably below about 50° C., such as a volatilealiphatic hydrocarbon or a volatile highly halogenated hydrocarbon, forexample, trichloromonofluoromethane, chlorotrifluoromethane,1,1-dichloro-1-fluoroethane, 1-chloro-1,1-difluoro-2,2-dichloroethaneand 1,1,1-trifluoro-2-chloro-2-fluorobutane or mixtures thereof.

Optional additives such as dispersing agents, cell stabilizers,surfactants, flame retardants, and the like which are commonly employedin the fabrication of rigid polyurethane foams, can be employed in theprocess of the invention. Thus, a finer cell structure may be obtainedif water-soluble organosilicone polymers are used as surfactants.Organosilicone polymers obtained by condensing a polyalkoxy polysilanewith the monoether of a polyalkyleneether glycol in the presence of anacid catalyst are representative of those surfactants which can be usedfor this purpose. The organosilicone copolymer available under the tradename L5420 is typical of such polymers. Other surfactants such asethylene oxide modified sorbitan monopalmitate or ethylene oxidemodified polypropyleneether glycol may be used, if desired, to obtainbetter dispersion of the components of the foam mixture.

Other additives such as dyes, pigments, soaps and metallic powders andother inert fillers may be added to the foam mixture to obtain specialfoam properties in accordance with practices well-known in the art.

The polyurethane foams produced using the novel polyols of the instantinvention are useful in a variety of commercial and industrialapplications including for example, the production of foam-insulation,structural foam sporting goods, and the like.

The following examples are provided to illustrate the present invention.Unless otherwise specified, all parts are by weight.

EXAMPLES

In the examples, the following materials were used:

POLYOL A: a 460 OH number polyol prepared by sequentially reacting 1mole of a 80/20 mixture of 2,4- and 2,6-toluene diamine with about 3.7moles of ethylene oxide and then with about 3.3 moles of propyleneoxide.

POLYOL B: a 395 OH number polyol prepared by sequentially reacting 1mole of a mixture of 2,3- and 3,4-toluene diamine with about 3.5 molesof ethylene oxide and then with about 4.5 moles of propylene oxide.

POLYOL C: a 380 OH number polyol prepared by sequentially reacting 1mole of the diamine mixture used in POLYOL B with about 4.3 moles ofethylene oxide and then with about 3.7 moles of propylene oxide.

POLYOL D: a 420 OH number polyol prepared by sequentially reacting 1mole of the diamine mixture used in POLYOL B with about 4.6 moles ofethylene oxide and then with about 3.6 moles of propylene oxide.

Y-10325: a polyalkyleneoxide/methyl siloxane copolymer surfactantavailable from Union Carbide.

PV: Desmorapid PV, a pentamethyldiethylenetriamine available fromRhein-Chemie.

PC-8: Polycat 8, a dimethylcyclohexylamine available from Air Products.

R-11: trichlorofluoromethane.

WATER

ISO: Mondur MR, a polymethylenepoly(phenylisocyanate) having anisocyanate content of about 31.5%, commercially available from MobayCorporation.

A handmixing technique was used to measure reactivity and foamingperformance of high and low density rigid foams. The temperature of theraw materials was kept at 20° C.±0.2° C. The B-side was prepared byweighing the polyol, surfactant, catalysts and R-11, in that order, intoa previously weighed mixing container. After mixing thoroughly, themixing container was reweighed and the evaporated R-11 was replaced. Toanother container was added the required amount of isocyanate. Thecontents of both containers were adjusted to 20° C.±0.2° C. Theisocyanate was then added to the B-side. The timer was started and thecomponents were mixed at 1000 rpm. The mixture was stirred for about 3seconds. After mixing was complete, the reaction mixture was poured intoa large paper container and the reaction times were recorded.

The products were then tested for k-factor (ASTM C-518) and densities(ASTM D-1622). The formulations were as indicated in Table 1, while thetest results were as set forth in Table 2.

                                      TABLE 1                                     __________________________________________________________________________    Example #                                                                             1  2   3  4   5   6   7   8   9* 10*                                  __________________________________________________________________________    Ingredients,                                                                  parts by weight                                                               B-Side:                                                                       POLYOL A                                                                              35.42                                                                            30.53                                                                             35.42                                                                            30.53                                                                             35.42                                                                             30.53                                                                             49.59                                                                             42.74                                                                             21.25                                                                            18.32                                POLYOL B                                                                              35.42                                                                            30.53                                                                             -- --  --  --  21.25                                                                             18.32                                                                             49.59                                                                            42.74                                POLYOL C                                                                              -- --  35.42                                                                            30.53                                                                             --  --  --  --  -- --                                   POLYOL D                                                                              -- --  -- --  35.42                                                                             30.53                                                                             --  --  -- --                                   PV      0.5                                                                              0.45                                                                              0.5                                                                              0.45                                                                              0.5 0.45                                                                              0.5 0.45                                                                              0.5                                                                              0.45                                 PC-8    1.0                                                                              1.35                                                                              1.0                                                                              1.35                                                                              1.0 1.35                                                                              1.0 1.35                                                                              1.0                                                                              1.35                                 Y-10325 1.0                                                                              1.0 1.0                                                                              1.0 1.0 1.0 1.0 1.0 1.0                                                                              1.0                                  WATER   1.66                                                                             1.14                                                                              1.66                                                                             1.14                                                                              1.66                                                                              1.14                                                                              1.66                                                                              1.14                                                                              1.66                                                                             1.14                                 R-11    25 35  25 35  25  35  25  35  25 35                                   A-Side                                                                        ISO     98.77                                                                            80.67                                                                             98.67                                                                            80.67                                                                             102.34                                                                            83.75                                                                             101.95                                                                            83.42                                                                             97.25                                                                            79.36                                Wt. Ratio                                                                     Non-vicinal:                                                                  Vicinal TDA                                                                           50:50                                                                            50:50                                                                             50:50                                                                            50:50                                                                             50:50                                                                             50:50                                                                             70:30                                                                             70:30                                                                             30:70                                                                            30:70                                Polyol                                                                        __________________________________________________________________________    Example #                                                                             11  12 13 14  15                                                                              16 17 18 19 20 21 22                                  __________________________________________________________________________    Ingredients,                                                                  parts by weight                                                               B-Side:                                                                       POLYOL A                                                                              46.05                                                                             39.69                                                                            24.79                                                                            21.37                                                                            42.5                                                                             36.64                                                                            28.32                                                                            24.42                                                                            38.96                                                                            33.58                                                                            31.88                                                                            27.48                               POLYOL B                                                                              24.79                                                                             21.37                                                                            46.05                                                                            39.69                                                                            28.34                                                                            24.42                                                                            42.50                                                                            36.64                                                                            31.88                                                                            27.58                                                                            38.96                                                                            33.58                               POLYOL C                                                                              --  -- -- -- -- -- -- -- -- -- -- --                                  POLYOL D                                                                              --  -- -- -- -- -- -- -- -- -- -- --                                  PV      0.5 0.45                                                                             0.5                                                                              0.45                                                                             0.5                                                                              0.45                                                                             0.5                                                                              0.45                                                                             0.5                                                                              0.45                                                                             0.5                                                                              0.45                                PC-8    1.0 1.35                                                                             1.0                                                                              1.35                                                                             1.0                                                                              1.35                                                                             1.0                                                                              1.35                                                                             1.0                                                                              1.35                                                                             1.0                                                                              1.35                                Y-10325 1.0 1.0                                                                              1.0                                                                              1.0                                                                              1.0                                                                              1.0                                                                              1.0                                                                              1.0                                                                              1.0                                                                              1.0                                                                              1.0                                                                              1.0                                 WATER   1.66                                                                              1.14                                                                             1.66                                                                             1.14                                                                             1.66                                                                             1.14                                                                             1.66                                                                             1.14                                                                             1.66                                                                             1.14                                                                             1.66                                                                             1.14                                R-11    25  35 25 35 25 35 25 35 25 35 25 35                                  A-Side                                                                        ISO     101.47                                                                            83.0                                                                             97.8                                                                             79.85                                                                            100.7                                                                            82.4                                                                             98.51                                                                            80.4                                                                             101.8                                                                            83.25                                                                            100.6                                                                            82.2                                Wt. Ratio                                                                     Non-vicinal:                                                                  Vicinal TDA                                                                           65:35                                                                             65:35                                                                            35:65                                                                            35:65                                                                            60:40                                                                            60:40                                                                            40:60                                                                            40:60                                                                            55:45                                                                            55:45                                                                            45:55                                                                            45:55                               polyol                                                                        __________________________________________________________________________     *9 and 10 are comparative examples                                       

                                      TABLE 2                                     __________________________________________________________________________    Example #   1   2   3  4  5  6   7  8   9  10  11                             __________________________________________________________________________    Test                                                                          Reactivity Times                                                              Cream (sec) 8   7   8  8  7  7-8 10 7-8 6  6   7                              Gel (sec)   39  37  37 40 36 38  39 37  37 37  38                             Flow (sec)  119 140 119                                                                              140                                                                              118                                                                              140 121                                                                              140 124                                                                              143 120                            Densities (pcf)                                                               Free Rise   1.35                                                                              1.08                                                                              1.37                                                                             1.09                                                                             1.36                                                                             1.08                                                                              1.30                                                                             1.11                                                                              1.28                                                                             1.12                                                                              1.34                           Molded Core 1.67                                                                              1.49                                                                              1.68                                                                             1.55                                                                             1.67                                                                             1.56                                                                              0.64                                                                             1.64                                                                              1.70                                                                             1.62                                                                              1.68                           Freeze Stable                                                                             1.92                                                                              1.74                                                                              1.93                                                                             1.77                                                                             1.99                                                                             1.75                                                                              1.86                                                                             1.86                                                                              1.87                                                                             1.86                                                                              1.86                           K-Factor (molded core)                                                        (BTU in/ft.sup.2 HR °F.)                                                           0.128                                                                             0.125                                                                             0.126                                                                            0.126                                                                            0.123                                                                            0.121                                                                             0.125                                                                            0.122                                                                             0.122                                                                            0.127                                                                             0.121                          % Difference of                                                               K-factor between                                                              densities       -2.3%  0     -1.6%  -2.4%  +4.1%                              __________________________________________________________________________    Example #   12  13 14  15 16  17 18  19 20  21 22                             __________________________________________________________________________    Test                                                                          Reactivity Times                                                              Cream (sec) 7   7-8                                                                              6   7-8                                                                              7   6  6   8  7   8  6                              Gel (sec)   36-37                                                                             37 36  37 36  37 37  37 36  36 36                             Flow (sec)  139 121                                                                              138 118                                                                              138 120                                                                              138 121                                                                              140 121                                                                              140                            Densities (pcf)                                                               Free Rise   1.11                                                                              1.34                                                                             1.13                                                                              1.33                                                                             1.10                                                                              1.33                                                                             1.10                                                                              1.34                                                                             1.12                                                                              1.31                                                                             1.10                           Molded Core 1.59                                                                              1.65                                                                             1.62                                                                              1.69                                                                             1.60                                                                              1.68                                                                             1.66                                                                              1.65                                                                             1.63                                                                              1.66                                                                             1.64                           Freeze Stable                                                                             1.84                                                                              1.85                                                                             1.84                                                                              1.86                                                                             1.84                                                                              1.86                                                                             1.90                                                                              1.86                                                                             1.86                                                                              1.86                                                                             1.86                           K-Factor (molded core)                                                        (BTU in/ft.sup.2 HR °F.)                                                           0.123                                                                             0.123                                                                            0.124                                                                             0.121                                                                            0.122                                                                             0.124                                                                            0.123                                                                             0.125                                                                            0.126                                                                             0.125                                                                            0.126                          % Difference                                                                              +1.7%  +1.0%  +1.0%  -1.0%  +1.0%  +1.0%                          __________________________________________________________________________

What is claimed is:
 1. A process for producing a polyurethane foamcomprising: reacting an organic di- and/or polyisocyanate with a polyolin the presence of a blowing agent, said polyol comprising:(a) an adductobtained by sequentially reacting 2,4- and/or 2,6-toluene diamine withfrom 3 to 5 moles of ethylene oxide and then with from 1 to 5.1 moles ofpropylene oxide, the total number of moles of ethylene oxide pluspropylene oxide being at least 5 and no more than 8.1, and (b) an adductobtained by sequentially reacting 2,3- and/or 3,4-toluene diamine withfrom 1 to 5 moles of ethylene oxide and then with from 1 to 6 moles ofpropylene oxide, the total number of moles of ethylene oxide pluspropylene oxide being at least 5 and no more than 9, the weight ratio ofcomponent (a) to component (b) being from 35:65 to 70:30.
 2. The processof claim 1 wherein the weight ratio of component (a) to component (b) isfrom 50:50 to 70:30.
 3. The process of claim 2 wherein said weight ratiois 50:50.
 4. A polyurethane foam produced by the process of claim 1.